Raid1 HD upgrade to larger drive help

I currently have a Raid1 configuration with dual 160gb HD’s. One of the drives has just degraded. I have 2 new WD Cavier Blue 320gb HD’s I want to upgrade to. What is the correct proceedure to go about transfering the OS/data from the smaller to the larger HD? I want to just increase the partition size without having to add any additional partitions.

Actually, those 2 Caviar Blue’s are not raid drives, and it’s probable that you will have continued issues with them dropping out of raid.  I’d consider cloning the raid drives you have and putting them on true raid drives.